It is well known that many dangerous communicable diseases are spread through contacting the body fluids of an infected person. After use of a sharps-containing medical device, residual body fluids are likely to remain on or within the sharp element of the medical device, for example needles or blades. After use, the sharp element should be covered, to prevent it from accidentally stabbing the person who is using the medical device, thereby potentially releasing residual bodily fluids into such a person. While caps can be used to cover sharps elements after use, there remains a risk that persons attempting to cap the sharp element may misapply the cap and accidentally pierce their skin with the used sharp element, resulting in potential exposure to communicable diseases.
Accordingly, it is desirable to provide for retraction of a sharps element inside of a medical device after the medical device has been used. For example, syringes having retractable needles are known, and syringes having pneumatically actuated retractable needles have been developed, as exemplified by U.S. Pat. Nos. 5,868,713 and 7,811,259, and Patent Cooperation Treaty patent application No. PCT/CA2015/051113, each of which is incorporated by reference herein. Often, such retractable needle syringes are provided as prefilled syringes. Modular needle assemblies designed to work with such retractable needles have also been developed, wherein the modular needle assembly can be fitted to a syringe of any desired size, for example as described in Patent Cooperation Treaty publication No. WO 2012/162821, which is incorporated by reference herein.
There remains a need to provide pneumatically actuated medical devices that are easier and/or less expensive to construct.
The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.